Hitachi UX Twin Nozzle Service Manual page 328

6.5.5 Disordered characters
Are the upper or
lower print dots
lost?
Is the upper end of
the print blotted?
There is a noise on
APH wave farm.
Yes
Confirm the print result
with the printhead removed
from customer's equipment.
.
Yes
Are normal prints
obtained?
Yes
Ask your customer to
remove any vibration.
Ensure that the work surface is
free from coating application
irregularities, water drops, dirt,
oil, and other foreign matter.
[Caution]
Do not repeat the nozzle backwash procedure more than two times.
If it is repeated in excess, the ink becomes thin, thereby causing disordered prints.
if the ink is thin and printings become disordered, replace the ink.
Disordered
characters
Yes
No
Yes
No
No
No
Since it is conceivable that the
ink flow path may be clogged,
replace the ink filter and MGV
filter, clean joints, backwash the
nozzle, and disassemble and
clean the nozzle.
6-86
See under "Chipped
print".
Is the operating
No
temperature with the
specified limits?
Ensure that the operating
Yes
temperature is within the
specified limits.
No
Are ink drops
properly generated?
Adjust the excitation voltage
Yes
and pressure to ensure
proper ink drops
generation.
No
Are normal prints
Yes
obtained?
No
Replace the ink.
Resume the
operation.
Are normal prints
obtained?
Yes